1. Field of Invention
The invention relates to a method of pattern etching a thin film, and more particularly to a method for transferring a pattern to a thin film using a mask layer while substantially consuming the mask layer to avoid a subsequent mask removal process.
2. Description of Related Art
As is known to those in the semiconductor art, interconnect delay is a major limiting factor in the drive to improve the speed and performance of integrated circuits (ICs). One way to minimize interconnect delay is to reduce interconnect capacitance by using low dielectric constant (low-k) materials during production of the ICs. Such low-k materials have also proven useful for low temperature processing. Thus, in recent years, low-k materials have been developed to replace relatively high dielectric constant insulating materials, such as silicon dioxide. In particular, low-k films are being utilized for inter-level and intra-level dielectric layers between metal layers of semiconductor devices. Additionally, in order to further reduce the dielectric constant of insulating materials, material films are formed with pores, i.e., porous low-k materials. Such low-k materials can be deposited by a spin-on dielectric (SOD) method similar to the application of photo-resist, or by chemical vapor deposition (CVD). Thus, the use of low-k materials is readily adaptable to existing semiconductor manufacturing processes. While low-k materials are promising for fabrication of semiconductor circuits, the present inventors have recognized that these films also provide many challenges. Both non-porous and porous low-k materials tend to be less robust than more traditional dielectric materials and can be damaged during wafer processing, such as by etch and plasma ashing processes generally used in patterning the dielectric materials.